FDI Notation, teeth's quadrants

FDI World Dental Federation notation (also "FDI notation" or "ISO 3950 notation") is the world's most commonly used dental notation (tooth numbering system).[1][2] It is designated by the International Organization for Standardization as standard ISO 3950 "Dentistry — Designation system for teeth and areas of the oral cavity".[3]

The system is developed by the FDI World Dental Federation. It is also used by the World Health Organization, and is used in most countries of the world except the United States (which uses the UNS).

Orientation of the chart is traditionally "dentist's view", i.e. patient's right corresponds to notation chart left. The designations "left" and "right" on the chart below correspond to the patient's left and right.

Table of codes

X-ray of the teeth and jaw showing the normal permanent teeth. The last two teeth on the patient's left (the dentist's right), 28 and 38 - the maxillary and mandibular third molars (popularly the upper and lower wisdom teeth) are severely impacted.
FDI two-digit notation
Permanent teeth
patient's upper right patient's upper left
18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28
48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38
patient's lower right patient's lower left
Deciduous teeth (baby teeth)
upper right upper left
55 54 53 52 51 61 62 63 64 65
85 84 83 82 81 71 72 73 74 75
lower right lower left
Comparison of alphanumeric notation, Palmer notation, ISO 3950 (FDI) notation, Universal Numbering System, and paleoanthropology notation

Codes, names, and usual number of roots: (see chart of teeth at Universal Numbering System)

How the codes are constructed

Syntax: <quadrant code><tooth code>

Sometimes a dot is inserted between quadrant code and tooth code in order to avoid ambiguity with other numbering systems, especially the UNS.

Quadrant codes
1 upper right permanent teeth
2 upper left permanent teeth
3 lower left permanent teeth
4 lower right permanent teeth
5 upper right deciduous teeth
6 upper left deciduous teeth
7 lower left deciduous teeth
8 lower right deciduous teeth
This is set by going clockwise from the dentist's view.
Tooth codes
1 central incisors
2 lateral incisors
3 canines
4 1st premolars (permanent teeth) / 1st molar (deciduous teeth)
5 2nd premolars (permanent teeth) / 2nd molar (deciduous teeth)
6 1st molars (permanent teeth)
7 2nd molars (permanent teeth)
8 3rd molars (permanent teeth)
This is defined by counting.


See also


  1. ^ FDI Two-Digit Notation Archived 2007-04-01 at the Wayback Machine, hosted on the FDI World dental Federation Archived 2007-07-18 at the Wayback Machine website. Page accessed April 1, 2007.
  2. ^ ISO (International Organization for Standardization). "ISO 3950:2016". ISO 3950:2016 Dentistry — Designation system for teeth and areas of the oral cavity. Retrieved 2023-03-10.
  3. ^ ISO 3950:2016 Dentistry — Designation system for teeth and areas of the oral cavity